163 resultados para ARYL HALIDES


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A mild and highly efficient copper-catalyzed system for N-arylation of alkylamines with aryl iodides using binaphthol-based phosphoramidites as ligands was developed. The phosphoramidite ligands are stable, cost-effective and easily prepared from inexpensive, commercially available starting materials using a simple, efficient method. (c) 2005 Elsevier B.V. All rights reserved.

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A highly efficient palladium-catalyzed Suzuki coupling of aryl bromides with aiylboronic acids using phosphoramidite ligand 2c was developed. The phosphoramidite ligands are cost-effective and easily prepared from inexpensive, commercially available starting materials using a simple, efficient method. It represents an advance toward the discovery of low-cost catalyst systems for eventual availability. (c) 2005 Elsevier B.V. All rights reserved.

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芳香卤化物是应用非常广泛的重要化工原料,多数具有强毒性和难以生物降解特性,对人类健康和自然环境造成了严重的威胁。催化加氢是一种先进、绿色处理技术,安全无毒物排放,降解产物还可以回收利用,受到研究者广泛关注。用催化加氢技术降解芳香卤化物具有应用价值和科学意义。 本文主要以Raney Ni为催化剂,氢气为氢源,研究了液相条件下,以氯苯为模型分子的催化加氢脱氯反应。详细讨论了在有机溶剂/水混合体系中溶剂、碱和温度等因素对催化剂活性和氯苯加氢脱氯的影响;探讨了催化剂失活的主要原因以及水促进催化剂活性和稳定性的原因;完善了一种适合降解氯代有机物的体系,并将其应用到了多氯代苯和持久性有机污染物

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渤海湾沿岸人口密集,工农、航运发达,渤海自身净化能力非常有限。因此,渤海湾 环境污染的压力越来越大,主要污染物包括重金属和持久性有机污染物的。四角蛤蜊广泛 分布于渤海湾海域,是一种重要的经济贝类,对污染物具有较强的富集能力。为了研究不 同站点渤海湾四角蛤蜊软体部重金属含量,选择大港油田、高沙岭码头、涧河村三个断面 进行研究,对不同站点四角蛤蜊软体部重金属含量进行了分析和讨论,最后对水生动物的 POPs 毒理调控通道进行了探索性研究,得到以下结果: 1. 通过比较渤海不同站点四角蛤蜊软体部重金属含量分布特征和方差分析,发现四 角蛤蜊软体部必需重金属元素含量较高,而非必需重金属元素含量较低,这是由于必需重 金属元素具有重要的生理功能作用。侧重比较A、B 两个断面各站位间四角蛤蜊软体部重 金属含量,发现虽然各站位间分布规律不明显,但各站位间差异显著。 2. 利用简单相关回归分析金属元素间及其与生物学性状间的关系,发现Mn 与Zn 之 间,Cu 与Zn 间均存在显著正相关,Se 与As、Cd 间存在显著正相关。另外,A 断面,BL 与Cd 含量显著负相关其回归方程为:Y(Cd)=-1395.97+88.34(BL);R=0.633;在B 断面,利用BW 和BH 分别与Cd 和As 显著负相关和显著正相关,其回归方程分别为:BW 和Cd 的回归方程为:Y(Cd)=-1968.80+220.72(BW);R=0.656。BH 和As 的回归方 程为:Y(As)=1496.86+227.82(BH);R=0.656。 3. 利用PLS(偏最小二乘分析)方法分析,发现五个生物学性状都与Co、As 呈正相 关,而与Cr、Pb、Se 呈负相关,而与必须重金属元素相关不明显。进一步分析表明表明 渤海湾海域中Co、As 含量低于四角蛤蜊正常生长发育的需要,而Cr、Pb、Se 的含量超过 四角蛤蜊正常生长发育所需的量。最后,通过PLS-DA 分析方法,发现C 站点样品能与A、 B 两个断面的站点区分开,而A、B 间未能区分开,反映了渤海湾三个断面的实际污染状 况。 4. 四角蛤蜊软体部重金属含量进行风险评价,首先,利用单因子污染指数法比较分析, 发现从1997 年-2008 年,渤海湾四角蛤蜊软体部Cd 的污染水平在不断降低,现在其含量 已低于《海洋生物质量标准》(第二类)标准。而Cr、As 有污染的趋势,需要引起重视。 然后,利用金属污染指数法进行比较研究,发现B 断面>A 断面>C 断面。最后,利用《人 体消费卫生标准》进行比较分析,发现Cd、Ni 存在轻度污染,因此需要加强其污染源的 控制。 5. 渤海湾污染物除了重金属外,还存在一些典型持久性有机污染物。为进一步揭示 二者间协同毒理机制,利用分子系统学方法,对芳香烃受体通道进行了探索性研究,发现 水生动物AhR通道基因在进化过程中发生了适应性进化,对进一步研究重金属和POPs对双 壳贝类的毒理机制具有参考价值。

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To characterize the contamination of anthropogenic organic contaminants in the aquatic environment of Chaohu Lake, China, 7 samples for both water and surface sediment were collected in the lake. Organic contaminants were extracted by solid phase extraction (SPE) and Soxhlet extraction from the water and surface sediment samples, respectively, and then analyzed by GC-MS. One hundred and twenty kinds of organic chemicals were detected in these samples including phenol, benzene series, benzaldehydes, ethanol, polycyclic aromatic hydrocarbons (PAHs), sulfur compounds, alcoholic halides, amines, ketones, esters, alkenes and alkanes. Among them, 13 kinds of chemicals were identified as priority pollutants listed by the U.S. Environmental Protection Agency (EPA), such as phthalate esters (PAEs) and PAHs. Besides, the concentrations of 19 of PAEs and PAHs including, priority pollutants identified were also determined. Bis(2-ethylhexyl)phthalate, the predominant component of the analyzed pollutants, was in the range from 72.34 ng g(-1) DW to 613.71 ng g(-1) DW, 14.80 ng L-1 to 47.05 ng L-1 in sediment and water, respectively. The results indicated that the northwest part of the lake was heavily polluted by domestic and industrial wastewater.

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Vitellogenin (Vtg) is the precursor of yolk protein. Its expression and secretion are estrogen-regulated and are crucial for oocyte maturation. An in vitro xenoestrogen screening model was established by measuring Vtg induction in cultured primary hepatocytes from crucian carp. Vtg production was detected by biotin-avidin sandwich ELISA method while Vtg and cytochrome P4501A1 (CYP1A1) mRNA induction were measured by semi- quantitative PCR-primer dropping technique. Vtg and Vtg mRNA were dose-dependently induced by diethylstilbestrol (DES, 0.2-200 ng/mL) in hepatocytes of crucian carp. Co-treatment of the DES-induced hepatocytes with either 2,3,7,8-TCDD (TCDD, 0.1-4 pg/mL) or benzo[a]pyrene (B[a]P, 5-1000 ng/mL) resulted in a reduction of Vtg production and an increment of CYP1A1 mRNA expression both in a dose dependent manner, indicating the anti-estrogenic effects of the compounds. However, at lower tested concentrations, TCDD (0.1, 0.2 pg/mL), B[a]P (5 ng/mL) seemed to have a potentiating effect on Vtg expression and secretion, although by their own these compounds had no observable estrogenic effect on Vtg induction. Tamoxifen (a selective estrogen receptor modulators, 1 nmol/L-1 mumol/L), and P-naphtho-flavone (beta-NF, an aryl hydrocarbon receptor inducing compounds, 2.5-1000 ng/mL) also were employed to study the possible interactions in DES-induced Vtg expression. In co-treatment of the DES-induced hepatocytes with beta-NF or tamoxifen, the decrease in Vtg production did parallel induction of CYP1A1 for beta-NF, but tamoxifen inhibited Vtg induction did not parallel induced CYP1A1 expression in all test concentrations. On the contrary, it was found that in co-treatment of the TCDD-induced hepatocytes with DES, TCDD induced CYP1A1 mRNA production was inhibited by DES also. These results implicated a possible cross talk between estrogen receptor- and aryl hydrocarbon receptor-mediated pathways in the hepatocytes.

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Aryl hydrocarbon (Ah) receptor (Ah-agonist) effects of environmental samples containing polychlorinated aromatic hydrocarbons were evaluated using a 7-ethoxyresorufin-O-deethylase (FROD) assay of a primary hepatocyte culture from grass carp (Ctenopharyngodon idellus). The results were compared with those obtained from the assay using the rat hepatoma cell line H4IIE and chemical analysis using high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). A dose-response relationship was observed between the EROD activities, either from primary hepatocyte culture assay or from H4IIE assay, and concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The results showed that the assay based on the H4IIE cell line (EC50 = 0.83 mug/mL) is more sensitive to TCDD than the assay based on primary hepatocyte Culture (EC50 = 9.7 pg/mL). In tests of environmental samples, the results from the assay using primary hepatocyte culture were comparable to those from the assay using the H4IIE cell line and chemical analysis of concentrations of mixtures of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/PCDF). The lack of a change in the activities of glutathione-S-transferase (GST) and lactate dehydrogenase (LDH) in cell culture upon exposure to TCDD indirectly indicates that the compound is persistent to biodegradation in the cell culture system. (C) 2004 Elsevier Inc. All rights reserved.

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The alternate combinational approach of genetic algorithm and neural network (AGANN) has been presented to correct the systematic error of the density functional theory (DFT) calculation. It treats the DFT as a black box and models the error through external statistical information. As a demonstration, the AGANN method has been applied in the correction of the lattice energies from the DFT calculation for 72 metal halides and hydrides. Through the AGANN correction, the mean absolute value of the relative errors of the calculated lattice energies to the experimental values decreases from 4.93% to 1.20% in the testing set. For comparison, the neural network approach reduces the mean value to 2.56%. And for the common combinational approach of genetic algorithm and neural network, the value drops to 2.15%. The multiple linear regression method almost has no correction effect here.

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Cupric iodide is a p-type semiconductor and has a large band gap. Doping of Mn, Co, and Ni are found to make gamma-CuI ferromagnetic ground state, while Cr-doped and Fe-doped CuI systems are stabilized in antiferromagnetic configurations. The origins of the magnetic ordering are demonstrated successfully by the phenomenological band coupling model based on d-d level repulsions between the dopant ions. Furthermore, using a molecular-orbital bonding model, the electronic structures of the doped CuI are well understood. According to Heisenberg model, high-T-C may be expected for CuI:Mn and CuI:Ni if there are no native defects or other impurities.

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联苯醚和芳基烷基醚类化合物是天然产物和聚合物材料中的重要的片段结构,研究其合成具有重要意义。近年来,过渡金属催化形成碳-氧键已成为制备联苯醚和芳基烷基醚类化合物的重要方法。钯体系虽然成功,但由于其属于贵金属,价格昂贵,而且反应所必须的有机膦配体,毒性较大,对环境危害较大,所以其应用受到了限制。 本论文通过利用空气稳定的Cu(bpy)2BF4 配合物,使得苯酚和烷基醇有效地进行偶合得到联苯醚产物。该方法可以在不使用昂贵弱碱Cs2CO3 的情况下,取得很好的产率,并且在较低的催化剂载入量的情况下,可以很好地适应各种官能团取代的底物。 本论文通过配体的扫描筛选,使得溴代苯和烷基醇的偶合反应得到了发展。更重要的是,使用该体系时分子间和分子内的碳-氧键都可以形成。通过该方法合成了一系列苯并环醚类化合物,这也是一价铜体系催化制备该类化合物的首次报道。

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聚芳醚酮是一种高性能热塑性材料,但其熔融温度高,熔体粘度大,流动性较差。液晶聚芳醚酮则具有非常丰富的液晶相织构和复杂的相转变行为,并且其熔体粘度低,流动性较好。将二者共混,液晶的加入势必降低聚芳醚酮的熔融粘度,改善其熔体流动性,另一方面液晶聚芳醚酮的液晶织构和相行为等势必受很大影响。因此开展这一研究工作不但有重要的理论意义,同时对改善这类材料的性能和拓宽其应用范围具有重要的实际意义。发现液晶聚芳醚酮/聚醚醚酮共混物的复杂相行为与组成密切相关。在以液晶聚芳醚酮为主的共混物中,高分子量的聚醚醚酮易于从低分子量的液晶聚芳醚酮基质相中分离出来,形成了特殊的环带结构。在50:50液晶聚芳醚酮/聚醚醚酮共混物中,两个组分在熔融状态下发生了液一液相分离,导致环带结构和聚醚醚酮球晶同时形成。在以聚醚醚酮为基质相的共混物中,低分子量的液晶聚芳醚酮很难从高分子量的聚醚醚酮基质相中分离出来,最后只能在聚醚醚酮球晶的边界形成单独的相区。当聚醚醚酮含量很高时,仅生成聚醚醚酮球晶。首次在液晶聚芳醚酮与聚醚醚酮共混物中发现了环带球晶,并利用溶剂选择性蚀刻的方法确定了其相结构和组成。环带球晶中的亮心和亮环是液晶聚芳醚酮相,其c轴(分子链方向)垂直于膜平面,而。和b轴则在膜平面内没有固定的取向。暗环则是聚醚醚酮与部分液晶聚芳醚酮的共存相,其中液晶聚芳醚酮晶体的分子链也垂直于膜平面,但聚醚醚酮片晶则呈现复杂的结晶取向。确定环带球晶的形成机理,从分子水平上提出环带球晶的生长模型,即间歇式增长过程,符合结构不连续模型。总结了环带球晶的形成规律和必要条件为:(l)液晶聚芳醚酮为主要成分;(2)液晶聚芳醚酮与聚醚醚酮有一定相容性,至少在熔融态分子相容;(3)液晶聚芳醚酮的各向同性相向液晶相的转变温度要高于聚芳醚酮的结晶温度;(4)液晶聚芳醚酮相转变(或结晶)速率与共混物的相分离速率相匹配或前者略大于后者;(5)降温速率或等温结晶温度适当。聚醚醚酮/含氟液晶聚芳醚酮共混物在熔体状态下的流动行为与共混物的组成、两相的相容性及相的转变有着密切的关系。在聚醚醚酮/含氟液晶聚芳醚酮共混物中,当前者为主要成份时,流动曲线形状与纯PEEK的相似,而当后者为主要成份时,表现出与含氟液晶聚芳醚酮相似的流变行为。共混物的复数粘度、储存模量和损失模量总体来说随F一队EK含量的增加而逐渐下降,只有当含氟液晶聚芳醚酮含量为50%时,共混物的复数粘度、储存模量和损失模量出现了局部极大值。

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本文对禄春安息香(Styrax macranthus)种子和攀援孔药花(Porandra scandens)全草的化学成分进行了研究,共获得30个化合物,其中2个为新化合物。 从禄春安息香种子95%乙醇提取物中分离并鉴定了12个化合物,其中2个新化合物鉴定为3-[7-methoxy-2-(3,4-methylenedioxy phenyl) benzofuran-5-yl] propyl 3-[7-methoxy-2-(3,4-methylenedioxyphenyl)benzofuran-5-yl] propanoate (1) 和去甲氧基-egonol-龙胆双糖甙 (2);已知化合物分别为2-(3,4-二氧亚甲基苯基)-5-甲酰基-7-甲氧基-苯并呋喃 (3)、egonol (4)、去甲氧基-egonol (5)、去甲基-egonol (6)、egonol-葡萄糖甙 (7)、egonol-龙胆双糖甙 (8)、egonol-龙胆三糖甙 (9)、豆甾醇 (10)、二十四烷酸 1-甘油酯 (11) 和胡萝卜甙 (12)。生物活性测试发现,化合物2具有促进雌激素E2合成的作用。 从攀援孔药花全草95%乙醇提取物中分离并鉴定了19个化合物:(2S,3S,4R)-2-[(2R)-2-羟基-二十一烷酰基氨基]-二十一烷-1,3,4-三醇 (13)、(2S,3S,4R)–2–二十四烷酰基氨基-十八烷-1,3,4-三醇 (14)、胡萝卜甙 (12)、β-谷甾醇 (15)、(20S,22E,24R)-5α,8α-表二氧-麦角甾-6,22-二烯-3β-醇 (16)、6β-羟基-豆甾-4-烯-3-酮 (17)、十六烷酸 1-甘油酯 (18)、桦木酸 (19)、大黄素 (20)、二十二烷酸 1-甘油酯 (21)、对羟基苯甲醛 (22)、十七烷酸 1-甘油酯 (23)、金色酰胺醇乙酸酯(24)、十九烷酸 1-甘油酯 (25)、棕榈酸 (26)、(E)-p-香豆酸 (27)、(22E,24S)-24-麦角甾醇-7,22-二烯-3β,5α,6β-三醇 (28)、2-去氧-β-蜕皮激素 (29)和auranamide (30)。 综述了近十年来发现的2-芳基苯并呋喃类新木脂素的结构特征、来源、生物活性和化学全合成。 Phytochemical investigation on the seeds of Styrax macranthus and the whole plants of Porandra scandens led to the isolation of thirty compounds, two of which were new ones. Two new 2-aryl benzofuran derivatives, 3-[7-methoxy-2-(3,4-methylenedioxy phenyl) benzofuran-5-yl]propyl 3-[7-methoxy-2-(3,4-methylenedioxyphenyl)benzo furan-5-yl]propanoate (1) and demethoxy egonol gentiobioside (2), were isolated from the 95% aqueous ethanolic extract of the seeds of Styrax macranthus, together with 7-methoxy-2-(3,4-methylenedioxyphenyl) benzofuran-5-carbaldehyde (3), egonol (4), demethoxy egonol (5), demethyl egonol (6), egonol glucoside (7), egonol gentiobioside (8), egonol gentiotrioside (9), stigmasterol (10), 2,3-dihydroxypropyl tetracosoate (11), and daucosterol (12). In vitro test, compound 2 promote the synthesis of estrogen E2. Nineteen compounds were isolated from the 95% aqueous ethanolic extract of the whole plant of Porandra scandens for the first time. Their structures were identified as (2S,3S,4R)-2-[(2R)-2-hydroxy-heneicosanoylamino]-1,3,4- heneicosanetriol (13), (2S,3S,4R)-2-tetracosanoylamino-1,3,4-octadecanetriol (14), daucosterol (15), β-sitosterol (12), (20S,22E,24R)-5α,8α-epidioxy-ergosta-6,22-diene- 3β-ol (16), 6β-hydroxylstigmast-4-en-3-one (17), 1-glycerol-1-hexadecoate (18), betulinic acid (19), emodin (20), 1-glycerol-1-docosoate (21), p-hydroxybenzaldehyde (22), 1-glycerol-1-heptadecoate (23), aurantiamide acetate (24), 1-glycerol-1- nonadecoate (25), palmatic acid (26), (E)-p-coumaric acid (27), (22E,24S)- 24-metbylcbolesta-7,22-diene-3β,5α,6β-triol (28), 2-deoxycrustecdysone (29), and auranamide (30). The characteristic, natural resource, bioactivity, and the total synthesis of 2-aryl benzofurans were reviewed.

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1-甲基-2-甲氧羰基-3, 6, 8-三羟基-7-甲氧基蒽醌是从唐菖蒲干球茎中分离到的具有环氧化酶-2选择性抑制活性的多取代蒽醌类化合物。本文试图合成该化合物,实现了其类似物的合成,同时发现了几个未见报道的反应。 1.通过Diels-Alder 反应合成了关键中间体——3-甲基-5-羟基-1, 2, 4-苯三甲酸三甲酯,1-COOMe选择性水解产物与1, 2, 3-三甲氧基苯进行分子间Friedel-Crafts反应的产物再进行分子内Friedel-Crafts反应得到了目标产物的类似物1-甲基-2-甲氧羰基-3-羟基-6,7,8-三甲氧基蒽醌(路线1)。目标产物及其它类似物的合成正在进行中。 2.以乙酰乙酸甲酯和巴豆醛为原料,经过Michael加成、分子内的Aldol反应、芳香化、选择性甲酰化和还原反应,得到关键中间体2-甲基-3-羟甲基-6-甲氧基苯甲酸甲酯及其衍生物。通过该化合物与3,4,5-三甲氧基苯甲酸甲酯进行Friedel-Crafts烷基化反应得到了多取代的二苯基甲烷衍生物,拟进一步关环合成目标化合物(路线2)。 3.发现邻甲氧基苯甲酸甲酯中酯甲基可以被正丁基锂和仲丁基锂中烷基交换生成相应的酯,反应的机理不明确。当使用叔丁基锂时,得到的是邻甲氧基苯基叔丁酮,这个方法可以用来合成芳基叔丁酮类化合物。 4.以2-苄氧基-6-甲基苯甲酸甲酯为原料进行氯甲基化反应时,以苯和二氯乙烷作溶剂,发生了苄基的迁移和芳环的偶联,分别得到2,2'-二甲基-3,3'-二甲氧羰基-4,4'-二羟基联苯和2,2'-二甲基-3,3'-二甲氧羰基-4,4'-二羟基-5,5'-二苄基联苯。这是对称联苯合成的新方法。 5.水杨酸羟基邻对位的选择性甲酰化可以分别通过水杨酸和水杨酸甲酯用HMTA/CF3COOH来实现。 6.Lewis酸催化3,4,5-三甲氧基苄醇环化成1, 2, 3, 6, 7, 8, 11, 12, 13-nonamethoxyl-10,15-dihydro-5H-trbibenzo [a, d, g] cyclononene (NDTC),产率(54%)高于已有方法(12%)。 Methyl 3,6,8-trihydroxy-7-methoxy-1-methylanthraquinone-2-carboxylate is a new COX-2 selective inhibitor isolated from Gladiolus gandavensis. Two strategies were investigated to synthesis this compound, in which some important reactions were discovered. 1. The key intermediate 5-hydroxy-3-methylbenzene-1,2,4-tricarboxylic acid 2,4-dimethyl ester was prepared via Diels-Alder reaction followed by selective hydrolysis of 1-COOMe. This compound was coupled with 1,2,3-trimethoxybenzene and the product undergo intramolecular Friedel-Crafts reaction to give methyl 3-hydroxy-5,6,7-trimethoxy-1-methylanthraquinone-2-carboxylate (1st route). The target compound and other analogues are being prepared with the same procedure. 2. The key intermediates methyl 3-hydroxymethyl-6-methoxy-2-methylbenzoate and its derivatives were prepared starting from crotonaldehyde and methyl acetoacetate via Michael addition, intramolecular aldol reaction, aromatization, formylation and reduction. The intermediates were coupled respectively with derivatives of gallic acid to give polysubstituted diphenylmethane. However, attempts to cyclize these compounds to the target compounds and analogues were not successful (2nd route). 3. In the process for ortho-lithiation of methyl 2-methoxybenzoate, the substrate converted respectively to n-butyl 2-methoxybenzoate and sec-butyl 2-methoxybenzoate when n-BuLi and sec-BuLi were used. However, tert-BuLi reacted with methyl 2-methoxybenzoate afford 2-methoxyphenyl tert-butyl ketone, which could be used to synthesize aryl tert-butyl ketones. 4. The transformtion of methyl 2-benzoxy-6-methylbenzoate to dimethyl 4,4'-dihydroxy-2,2'-dimethylbiphenyl-3,3'-dicarboxylate in benzene, and dimethyl 5,5'-dibenzyl-4,4'-dihydroxy-2,2'-dimethylbiphenyl-3,3'-dicarboxylate in 1,2-dichloroethane in the presence of ZnCl2 provides a new method for the synthesis of symmetric biphenyl. 5. The formylation of salicylic acid at C-5 and methyl 2-hydroxybenzoate at C-3 could be regioselectively realized by using HMTA/CF3COOH. 6. Racemic 1, 2, 3, 6, 7, 8, 11, 12, 13-nonamethoxyl-10, 15-dihydro-5H-trbibenzo [a, d, g] cyclononene was prepared via Lewis acids catalyzed trimerization of 3, 4, 5-trimethoxylbenzyl alcohol with yield (54%) higher than the reported procesure (12%).